Severe clashes were reported at the Damascus neighborhood of al-Abbaseen overnight between the Syrian government forces and the Free Syrian Army (FSA), Al Arabiya reported on Monday citing the Syrian Media Center.

As many as 21 people have been killed on Monday in Deir Ezzor, Idlib, Hama and Homs, activists at the Local Coordination Committees said.

The deaths come one day after at least 59 people have been killed by the Syrian forces on Sunday, activists at the Syrian Revolution Commission said. The victims, mostly in Homs, included five women and a photojournalist, they said.

Loud explosions were reported at al-Saleeba in Lattakia; while al-Heffa region was shelled by missiles and mortar shells, activists said.

Intensive shelling was reported in al-Attareb region in Aleppo amid fears of possible new massacre in the region, activists at the Local Coordination Committees said.

Shelling was also reported in Harasta in Damascus suburbs; Karnaz in Hama and al-Ashara in the outskirts of Deor Ezzor, where clashes were reported between government forces and rebel troops.

The new head of Syria’s main opposition group called Sunday for mass defections from a Syrian regime struggling to survive by carrying out massacres, as the death toll in the uprising topped 14,000.

Similar calls were made by the rebel FSA, which also urged a campaign of mass “civil disobedience” to ratchet up internal pressure on President Bashar al-Assad’s beleaguered regime.

“We are entering a sensitive phase. The regime is on its last legs,” Kurdish activist Abdul Basset Sayda told Al Arabiya shortly after being named the new leader of the opposition Syrian National Council (SNC).

“The multiplying massacres and shelling show that it is struggling,” he said of mass deaths of civilians, the most recent of which saw 20 people, mostly women and children, killed in a bombardment of the southern city of Deraa Saturday.

At his first news conference since taking over the reins, Sayda called on all members of the Damascus regime to defect, while reaching out to minority groups by promising them a full say in a future, democratic Syria.

Calling for a campaign of civil disobedience

We call on Syrians to launch a general strike leading to mass civil disobedience

Syria Colonel Kassem Saad Eddine, FSA

The FSA, meanwhile, called for a campaign of civil disobedience and urged officers and troops in Assad’s military to jump ship and join the rebel ranks.

“We call on Syrians to launch a general strike leading to mass civil disobedience,” FSA spokesman in Syria Colonel Kassem Saad Eddine said in a statement, according to AFP.

He urged officers and men in Syria’s regular army “whose hands are not tainted with blood to join the fighters.”

New SNC chief Sayda replaced Paris-based academic Burhan Ghalioun, who stepped down last month in the face of mounting splits that were undermining the group’s credibility.

Activists accused Ghalioun of ignoring the Local Coordination Committees, which spearhead anti-government protests on the ground in Syria, and of giving the Muslim Brotherhood too big a role.

“We would like to reassure all sects and groups, especially Alawites and Christians, that the future of Syria will be for the all of us,” Sayda said.

“The Annan plan still exists but it has not been implemented,” he said of a peace blueprint thrashed out by U.N.-Arab League envoy Kofi Annan that was supposed to begin with a ceasefire from April 12 but which has been violated daily.

“We will work for this plan to be included under Chapter VII of the U.N. Charter, to force the regime to implement it and to leave all options open,” Sayda said.

Looking like Bosnia in the 1990s

It is looking more like Bosnia in the 1990s, of being on the edge of a sectarian conflict in which neighboring villages are attacking and killing each other

British Foreign Secretary William Hague

Russia and China, infuriated by the NATO campaign in Libya last year, have vowed to oppose any military intervention, but British Foreign Secretary William Hague refused on Sunday to rule out the possibility.

“We don’t know how things are going to develop. Syria is on the edge of a collapse or of a sectarian civil war, and so I don't think we can rule anything out,” Hague told Sky News television.

“It is looking more like Bosnia in the 1990s, of being on the edge of a sectarian conflict in which neighboring villages are attacking and killing each other.”

The violence has intensified despite the presence of 300 United Nations observers charged with monitoring the putative truce.

Opposition sources said the election of Sayda could help enlist more Kurds, who number one million out of Syria’s 21 million population, behind the 15-month uprising, Reuters reported.

Demonstrations against Assad’s rule have been regularly breaking out in Kurdish regions of Syria but without matching the intensity of protests in the rest of the country.

That may be partly because of support by Assad for the armed Kurdistan Workers Party (PKK), which is suspected of being behind assassinations of several anti-Assad Kurdish opposition figures since the revolt erupted.

Kurdish members of the council have had open disputes with the remainder of the body over the issue of Kurdish rights and whether a post-Assad Syria would be built around a federal structure similar to that in neighboring Iraq.

The latest deaths bring to more than 14,100 the number of people killed since March last year, including 9,862 civilians, 3,470 soldiers and 783 army deserters, the Syrian Observatory for Human Rights said.